In the pharmaceutical industry tablets and caplets have been coated in many ways to enhance their market appeal and to enhance their swallowability. Early work generally used sugar coatings. Later polymer coatings, often requiring the use of non-aqueous solutions, were popular, but because of environmental concerns were replaced at least in the United States by aqueous coating techniques. Thin coatings of cellulose polymers are commonly used to enhance swallowability and as undercoatings to facilitate the addition of other coatings, such as enteric coatings.